Remove references to legacy visibility system (#4441)

* remove look at interpolation position

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* remove visibility switch

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* remove references to object cache

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* add some more asserts to catch code that should never run

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* add missing [[maybe_unused]]

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* revert clang-format change

Signed-off-by: hultonha <hultonha@amazon.co.uk>

Code/Editor/Viewport.h

@@ -491,10 +491,6 @@ public:
     void ResetCursor() override;
     void SetSupplementaryCursorStr(const QString& str) override;
 
-    //////////////////////////////////////////////////////////////////////////
-    // Return visble objects cache.
-    CBaseObjectsCache* GetVisibleObjectsCache()  override { return m_pVisibleObjectsCache; };
-
     void RegisterRenderListener(IRenderListener*    piListener) override;
     bool UnregisterRenderListener(IRenderListener*  piListener) override;
     bool IsRenderListenerRegistered(IRenderListener*    piListener) override;
@@ -612,8 +608,6 @@ protected:
     int m_nLastUpdateFrame;
     int m_nLastMouseMoveFrame;
 
-    CBaseObjectsCache* m_pVisibleObjectsCache;
-
     QRect m_rcClient;
 
     AZ_PUSH_DISABLE_DLL_EXPORT_MEMBER_WARNING